Research On Oil Layer Classification Of Lower Wuerhe Formation Reservoir In Ma 2 Well Block Of Mabei Oilfield

According to the problem of the difference of single well productivity,the production effect of the test well group is different,the water injection effect is not obvious and the interlayer heterogeneity is strong,the contradiction is prominent in the study area.This study is under comprehensive analysis of the reasons for the problems in lithology,physical properties,oil bearing,I was studied on the problem according to the difference of single well productivity,production effect after fracturing is different in different wells and the different segment of same well,the water injection effect is not obvious,the interlayer heterogeneity is strong,the contradiction is prominent.According to the characteristics of reservoir lithology,physical property,establish the interpretation chart;classify reservoir further,comprehensive research on all kinds of oil reservoirs,according to the different distribution of various types of reservoir in the plane,summarize the features and regularity of different type of reservoirs,establish the concept of overall structure distribution of oil reservoirs.Through research,the following results were obtained:(1)According to core observation,thin sections,logging data and characteristics of log response,lithology interpretation chart is established,lithology is divided into traction current medium conglomerate,gravity current medium conglomerate,traction current fine conglomerate,gravity current fine conglomerate,traction current small conglomerate,gravity current small conglomerate,traction current sandstone,gravity current sandstone,pelitic siltstone,mudstone.(2)Lower Urho Formation belongs to low porosity and specially low permeability type,the average porosity is 6.39%,the average permeability is 12.78mD,the porosity of reservoir is mainly distributed in the range of 3%?9%,the permeability of reservoir is mainly distributed in 0.1 mD?12.25mD.According to laboratory analysis data,logging data,Porosity interpretation chart is established.(3)It is obvious that distinguish point of different crude oil properties in logging crossplot of single well,oil reservoir is distinguished obvious in AC-CNL and AC-GR crossplot of Ma 2 and Ma 003,but non-oil reservoir is not distinguished,it explain that the oil reservoir can be divided according to the crude oil properties.(4)According to oil properties,reservoir type is divided into four types:light oil reservoir A,light oil reservoir B,medium oil reservoir,heavy oil reservoir.All kinds of reservoir classification standard is confirmed.(5)The light oil reservoir A is characterized by small conglomerate,porosity between 7%and 10%,permeability between 0.1 mD and 12.25mD,oil spot.The light oil reservoir B is characterized by small conglomerate and fine conglomerate,porosity between 6%and 9%,permeability between 0.1mD and 30mD,oil spot.The medium oil reservoir is characterized by small conglomerate and fine conglomerate,porosity between 7%and 10%,permeability between 0.1mD and 5mD.heavy oil reservoir is characterized by small conglomerate,lower porosity,lower permeability.(6)The thickness of the light oil reservoir A and light oil reservoir B is the largest,which is mainly distributed in the eastern part of the P2w21 layer and the P2w22 zayer.The thickness of the medium oil reservoir is small,which is mainly distributed in the vicinity of Ma 4.The thickness of heavy oil reservoir is smaller,which is mainly distributed in the P2w22 layer and the P2w1 layer.